Coherently Stacked Boron Nitride Nanotubes with a Strong Nonlinear Chiroptical Response

Chiral nonlinear optical materials enable optical frequency conversion such as second harmonic generation (SHG) and exhibit differential responses to left- or right-circularly polarized light (known as circular dichroism (CD)). This property allows for the modulation of the polarization of nonlinear parametric light [1], which is highly sought after for many advanced applications including nonlinear holographic imaging and quantum information processing. However, a trade-off exists between achieving efficient SHG output and strong chirality in conventional materials. Despite significant efforts, the demand for intrinsic chiral materials that offer high stability, pronounced optical nonlinearity and a large chiroptical response still remains challenging [2].